Population pharmacokinetic/pharmacodynamic analysis of PEG-rhGH enhances confidence in exploring dosing schemes with longer intervals.

BACKGROUND AND OBJECTIVES: PEG-rhGH (Jintrolong®, 0.2 mg/kg/week) is approved in China for the treatment of growth hormone deficiency (GHD) in children. Although 0.2 mg/kg/2 weeks PEG-rhGH failed the non-inferiority threshold of 20% compared with 0.2 mg/kg/week PEG-rhGH, it notably increases serum IGF-1 levels and height velocity in a phase IV trial. In the absence of investigation on the relationship between pharmacokinetics and pharmacodynamics, this analysis aimed to build a population pharmacokinetic/pharmacodynamic (PopPK/PD) model to characterize the relationship between serum PEG-rhGH concentration and serum insulin-like growth factor-1 (IGF-1) levels after subcutaneously administration of PEG-rhGH and to explore the possibility of flexible dosing schemes and improve the clinical monitor practice of IGF-1 levels. METHODS: A total of 41 subjects were included for the PopPK analysis, consisting of 30 healthy adults (single dose of 0.1-0.4 mg/kg) and 11 GHD children (multiple doses of 0.2 mg/kg/2 weeks for 26 consecutive weeks). Only GHD children were included for the PopPK/PD analysis. The time courses of serum PEG-rhGH concentrations in healthy adults and GHD children and those of serum IGF-1 levels stimulated by serum PEG-rhGH were well developed with non-linear mixed-effects modeling. RESULTS: Serum PEG-rhGH pharmacokinetics after subcutaneous administration were adequately described by a one-compartment model with a zero-order input into the absorption compartment followed by first-order absorption dictating absorption into the central compartment, with a dual elimination process consisting of a capacity limited process and a non-capacity limited process. Body weight was a significant covariate. The drug effects on IGF-1 levels were adequately described by a turnover model with saturable effect relationship. IGF-1 responses at the various dosing scheme scenarios were simulated, and illustrated that dosing schemes with intervals longer than the approved one week could be promising, which may provide comparable peaks and average IGF-1 levels and IGF-1 SDS to dosing schemes that have been clinically proven to be tolerated and effective. An accurate prediction of the time course of the effect of various dosing schemes may assist the clinical monitoring practice. CONCLUSIONS: This pharmacokinetic/pharmacodynamic analysis suggested that longer intervals or higher dosing strengths (e.g., 0.3 mg/kg/10 days) in children with GHD are promising compared with the approved dosing scheme (0.2 mg/kg/week). Our simulation may assist the clinical monitoring of the PEG-rhGH therapy.

Generation of an isogenic gene-corrected iPSC line (OGHFUi001-A-1) from a type 1 early infantile epileptic encephalopathy (EIEE1) patient with a hemizygous R330L mutation in the ARX gene.

Type 1 early infantile epileptic encephalopathy (EIEE1) is a rare X-link neurodevelopmental disorder caused by mutations in the ARX gene. The mechanism remains unclear due to the lack of cellular models for the disease. We previously have generated an iPSC line (OGHFUi001-A) from a male EIEE1 patient with a hemizygous R330L mutation in the ARX gene. Here we corrected the R330L mutation genetically using CRISPR/Cas9 technology to generate an isogenic control, which was an ideal control to investigate the pathogenesis of the mutation in this disease.

Genetic aetiology of primary adrenal insufficiency in Chinese children.

BACKGROUND: Primary adrenal insufficiency (PAI) is life-threatening, and a definitive aetiological diagnosis is essential for management and prognostication. We conducted this study to investigate the genetic aetiologies of PAI in South China and explore their clinical features. METHODS: Seventy children were enrolled in this cross-sectional study. Clinical information was collected, and combined genetic tests were performed according to the children's manifestations. Statistical analysis was performed among the different groups. In silico or in vitro experiments were applied to determine the pathogenicity of novel variants. RESULTS: Among the 70 children, 84.3% (59/70) were diagnosed with congenital adrenal hyperplasia (CAH), and 21-hydroxylase deficiency (21-OHD) was genetically confirmed in 91.5% of these cases. Salt wasting (SW), simple virilization (SV), and non-classic (NC) CAH accounted for 66.1% (39/59), 30.5% (18/59), and 3.4% (2/59) of the cases, respectively. The 17-hydroxyprogesterone (17-OHP) and testosterone (TES) levels were significantly higher in children with SW than with SV. The 17-OHP and cortisol levels in female SW patients were significantly higher than those in males. The 17-OHP, cortisol, dehydroepiandrosterone (DHEAS) and TES levels in female SW patients were significantly higher than those in female SV patients. Additionally, 72.7% (8/11) of uncharacterized PAI patients had positive genetic findings. Among all the patients, two novel variants in the CYP21A2 gene (c.833dupT and c.651 + 2T > G) were found. A microdeletion (Xp21.2-21.3) and five novel variants, including 2 in the NR0B1 gene (c.323-324CG > GA and c.1231_1234delCTCA), 2 in the AAAS gene (c.399 + 1G > A and c.250delT) and 1 in the NNT gene (c.2274delT), were detected. The novel variant c.399 + 1G > A in the AAAS gene was further confirmed to lead to exon 4 skipping during mRNA transcription and produce a truncated ALADIN protein. CONCLUSIONS: We found ethnicity-based differences in the CYP21A2 gene variant spectrum among different study populations. Female 21-OHD patients tended to have higher 17-OHP and TES levels, which warrants caution in relation to the effects of virilization. Novel gene variants detected in the CYP21A2, NR0B1, AAAS and NNT genes expanded the genetic spectrum of PAI, however, further improvement of genetic testing tools beyond our protocol are still needed to uncover the complete aetiology of PAI in children.

Phenotypes and epigenetic errors in patients with Beckwith-Wiedemann syndrome in China.

BACKGROUND: Beckwith-Wiedemann syndrome (BWS) is primarily caused by epigenetic errors. This study aimed to analyze the relationship between the epigenetic errors and phenotypes of BWS and to evaluate the efficacy of diagnosing BWS using patients' clinical characteristics. METHODS: Patients clinically diagnosed with BWS were subjected to methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) for (epi)genotyping. The patients' clinical characteristics were analyzed and compared using regression models. The diagnostic efficacy of previous criteria and scoring systems was compared using area under the receiving operating curve (ROC). RESULTS: The most common clinical features observed in BWS patients were macroglossia (83.2%), abdominal wall defects (71.3%), and ear creases/pits (55.3%). Patients with the loss of methylation at imprinting control 2 (IC2-LOM) and gaining of methylation at imprinting control 1 (IC1-GOM) subtypes had significantly higher frequencies of ear creases/pits and facial nevus flammeus, and visceromegaly, respectively. Paternal uniparental isodisomy (pUPD) was characterized by significantly less macroglossia but more hemihypertrophy. The area under the curve (AUC) was comparably good in both recently developed scoring systems (0.87 for Ibrahim and 0.82 for Brioude.) and in the scoring system developed using the current cohort (0.88). CONCLUSIONS: This study, which is the largest cohort study of BWS cases in China published to date, confirmed the diagnostic efficacy of a recently developed symptom-based BWS scoring system in a Chinese population. Significant differences exist between the phenotypes of BWS epigenetic subtypes; however, the pattern is similar between Asian and European populations.

Generation of an induced pluripotent stem cell line (CHFUi001-A) from an osteogenesis imperfecta patient with COL1A2 mutation.

Osteogenesis Imperfecta (OI) is a rare autosomal dominant metabolic disorder caused by heterozygous mutations in the COL1A1 or COL1A2 genes, which encode the pro-α1(I) and pro-α2(I) chains of type I procollagen, respectively. A human induced pluripotent stem cell (iPSC) line, termed as CHFUi001-A, was generated from peripheral blood mononuclear cells (PBMCs) of a 5-year-old female patient with OI, who had a heterozygous (c.928G > A:p.G328S) mutation in the COL1A2 gene, using non-integrating episomal vector technique. CHFUi001-A offers a useful resource to investigate pathogenic mechanisms in OI, as well as a cell-based model for drug development to treat OI.

[Association of body fat ratio with precocious puberty in girls].

OBJECTIVE: To study the association of body fat ratio with precocious puberty in girls. Previous studies have shown that body mass index (BMI) is associated with the girls' age of puberty but have not revealed the association of body fat ratio with age of puberty. METHODS: Based on the consensus on the diagnosis and treatment of central precocious puberty (CPP), 128 children with precocious puberty who were admitted to the hospital from July to August, 2017, were divided into a CPP group with 87 children and a peripheral precocious puberty (PPP) group with 41 children. A total of 51 girls without any puberty development signs were enrolled as the control group. Dual-energy X-ray absorptiometry was used to measure the body fat ratios of upper limbs, legs, trunk, android area, gynoid area, and the whole body. The association between body fat ratios and precocious puberty was analyzed with reference to age, BMI, BMI-Z score, bone age, ovarian volume, and hormone levels. RESULTS: Compared with the control group, the CPP and PPP groups had significantly higher body fat ratios of upper limbs, legs, trunk, android area, gynoid area, and the whole body, legs/whole body fat ratio, and (upper limbs+legs)/trunk fat ratio (P<0.05), while there were no significant differences in the above body fat ratios and fat distribution indicators between the CPP and PPP groups (P>0.05). For the girls with precocious puberty, the high body fat ratio group had significantly higher luteinizing hormone (LH) base value, luteinizing hormone releasing hormone (LHRH)-stimulated LH peak value, and LH/follicle-stimulating hormone peak value than the low body fat ratio group (P<0.05). Compared with the control group, both the high body fat ratio and low body fat ratio groups had a significantly higher LH base value (P<0.05). CONCLUSIONS: The increase in body fat may be a factor inducing precocious puberty in girls, but further studies are needed to determine the mechanism.

Genotype and phenotype correlation in a cohort of Chinese congenital hypothyroidism patients with DUOX2 mutations.

BACKGROUND: This study aimed to explore the relationship between the phenotype and genotype of congenital hypothyroidism (CH) caused by dual oxidase 2 (DUOX2) mutation in Chinese children, and to investigate the genetic causes of permanent and transient hypothyroidism through next-generation genetic testing technology and long-term clinical follow-up data. METHODS: We recruited 61 patients with thyroid stimulating hormone (TSH) levels of >10 mIU/mL during newborn screening, clinical diagnosis of CH, and L-thyroxine (L-T4) oral treatment within 1 month of birth; they were followed up until the present. All CH infants and their parents were genotyped using whole-exome sequencing (WES); DUOX2 variants were detected in 20 infants, and the longitudinal prognosis, genotype, and phenotype correlations were analyzed. RESULTS: Biallelic DUOX2 mutations were detected in 20 participants. All of them were born full term. All patients were treated with L-T4 when diagnosed with CH; 9 of them stopped L-T4 eventually before 3 years old; and 2 were treated with a reduced dose of L-T4 (12.5 µg per day). The others were still treated with L-T4 at a dose of 37.5-87.5 µg per day. Of these 20 participants, 5 carried an R1110Q variant and 5 carried K530X variants. A total of 7 novel variants were discovered in our cohort. The variants carried in transient CH patients were located extracellularly and not near the functional domain. CONCLUSIONS: Most CH patients with DUOX2 mutations were those with transient or subclinical CH. The R1110Q, R885L, and K530X were the most common variants in our Chinese cohort. The R1110Q and K530X variants may play a founder effect in the transient CH. The R885L variant may play a benign role in transient CH. Intracellular variants or those near the functional domain may cause permanent CH.

Genotype and phenotype analysis of a cohort of patients with congenital hyperinsulinism based on DOPA-PET CT scanning.

Congenital hyperinsulinism (CHI) is a clinically, genetically, and morphologically heterogeneous disorder. 18F DOPA-PET CT scanning greatly improves its clinical outcome. Here, we presented the first Chinese 18F DOPA-PET CT scanning-based CHI cohort highlighting the variable ethic clinical phenotypes and genotypes. Fifty CHI patients were recruited. Median age at presentation was 2 days. Median fasting time was 2 h. Mean insulin level was 25.6 µIU/ml. Fifty-two percent of patients were diazoxide-unresponsive with significantly shorter fasting tolerance time and higher serum insulin level compared with the responsive patients. Seventy-four percent of patients experienced at least one adverse drug reaction. Tremendously increased focal lesions (32%) were detected and 75% of them were cured through surgery. Thirty-one nucleotide sequence changes were identified in 48% patients. Four novel variants (Q608X, Q1347X, Q289X, F1489S) in ABCC8 gene and 2 novel variants (G132A, V138E) in KCNJ11 gene were detected. Of the variants, 87.1% harbored in ABCC and KCNJ11 genes. T1042Qfs*75 in ABCC8 gene was the most common mutation.Conclusion: Highly increased portion of focal lesion was presented in Chinese CHI patients compared with that of the previous reports. Intolerance to diazoxide was much more evident in Chinese or East Asian than other populations. Certain hotspot mutations harbored in Chinese CHI patients. What is Known: • 18F DOPA-PET CT scanning can provide informative guidance for surgical procedure when medical therapy is not well responded in CHI patients. What is New: • Intolerance to diazoxide is much more evident in Chinese and East Asian CHI patients compared with the other ethnic populations. • Novel mutations were detected in ABCC8 and KCNJ11 gene. Hotspot mutations such as T1042Qfs*75, I1511K, E501K, G111R in ABCC8 gene, and R34H in KCNJ11 gene are predominantly responsible for Chinese CHI patients.

Clinical characteristics and beta-cell function of Chinese children and adolescents with type 2 diabetes from 2009 to 2018.

BACKGROUND: The limited available studies have unveiled different natural histories and prognosis associated with pediatric type 2 diabetes (T2D) and adult T2D. To date, data on the clinical features, metabolic profiles and beta-cell function characteristics are still limited in the Chinese pediatric T2D population. METHODS: A total of 56 children with T2D, 31 with prediabetes and 159 with obesity were recruited. Clinical characteristics, metabolic profiles, beta-cell function and insulin resistance were analyzed. RESULTS: The mean onset age of T2D was 12.35 ± 1.99 (7.9-17.8) years, and 7% of children were younger than 10 years; 55% of them were male, 57% had a family history of diabetes and 64% had classic symptoms, and 25% had a low or high birth weight. 89% of T2D patients were obese or overweight. A total of 58% of the patients with prediabetes were male. The fast serum C-peptide level was highest in the obesity group (P < 0.001), and there was no significant difference between the T2D and prediabetes groups. The mean homeostatic model of assessment of beta-cell function was the highest in the obesity group and was lowest in the T2D group (P < 0.001). The T2D group had the most serious lipid metabolism disorder, with the highest levels of total triglycerides, total cholesterol, and low density lipoprotein and the lowest high density lipoprotein level among the three groups. CONCLUSIONS: A younger onset age and greater male susceptibility were found in Chinese pediatric T2D patients, and there was a stepwise deterioration trend in beta-cell function among patients with obesity, prediabetes and T2D. Based on our results, together with the SEARCH study results, an early screening and intervention program for T2D is recommended in high-risk or obese Chinese pediatric populations starting at 7 years.

[Recurrent anorexia and pigmentation of skin for more than two months in an infant].

A 2-month-old boy presented with adrenal insufficiency, impaired liver function, hypertriglyceridemia, significantly elevated creatine kinase and electrolyte disturbance. Microarray comparative genomic hybridization (aCGH) analysis test showed a pathogenic 8.7 Mb deletion in the short arm of chromosome X (Xp21.3 - p21.1) and confirmed the diagnosis of complex glycerol kinase deficiency (cGKD). He was treated with hydrocortisone, coenzyme Q10 and L-carnitine and was subsequently followed up for 4 years. His serum cortisol levels returned to normal one week later after treatment, but the serum creatine kinase, triglyceride and aminotransferase levels were progressively increased along with mental retardation and decreased muscular strength. cGKD is also named as Xp21 contiguous gene syndrome. The clinical manifestations of this disease include hypertriglyceridemia, congenital adrenal hypoplasia (AHC), Duchenne muscular dystrophy, and mental retardation. This case highlights the necessity to screen the serum triglyceride and creatine kinase levels in infants with suspected adrenal insufficiency.

Relationship between initial treatment effect of recombinant human growth hormone and exon 3 polymorphism of growth hormone receptor in Chinese children with growth hormone deficiency.

The aim of this study is to investigate the frequency distribution of exon 3 deleted (d3-GHR) genetic polymorphism of growth hormone receptor (GHR) in growth hormone deficient (GHD) Chinese children and to explore the correlation between the growth promoting effects of recombinant human growth hormone (rhGH) and exon 3 genetic polymorphism of GHR in GHD children. In this study, 111 GHD (excluded small for gestational age) children were treated with rhGH (0.20 mg/kg/week) for six months. The body height (Ht), body weight, bone age (BA) and growth velocity (GV) were measured before and after six months of treatment. The d3-GHR and full length GHR (fl-GHR) were analyzed to detect the frequency distribution of two isoforms and their influence on growth promoting effect of rhGH. The results indicated that the frequencies of fl/fl, fl/d3 and d3/d3 GHR genotypes were 67.6%, 18.9% and 13.5%. After six months of GH therapy, there were significant differences of ΔGV (ΔGV: 10.77±3.40 cm/year vs 12.18±3.08 cm/year) (P<0.05) and ΔHt (ΔHt: 5.38±1.70 cm vs 6.09±1.54 cm) (P<0.05) were found among GHD children with different genotypes (fl/fl vs fl/d3 and d3/d3). In conclusion, the frequency distribution of three GHR genotypes in 111 Chinese GHD children was different from that reported in Caucasian, indicating the existence of ethnic difference of exon 3 GHR polymorphism. There was a closely relationship between GHR genotypes and growth-promoting effect of rhGH in Chinese GHD children.

Rapidly rising incidence of childhood type 1 diabetes in Chinese population: epidemiology in Shanghai during 1997-2011.

The aim of this study was to investigate incidence trend of childhood type 1 diabetes in Shanghai, a megalopolis in east China. We established a population-based retrospective registry for the disease in the city's registered population during 1997-2011 and collected 622 incident type 1 diabetes in children aged 0-14 years. Standardized incidence rates and 95 % CI were estimated by applying the capture-recapture method and assuming Poisson distribution. Incidence trend was analyzed using the Poisson regression model. The mean annual incidence of childhood type 1 diabetes was 3.1 per 100,000 person-years. We did not observe significant difference in incidence between boys and girls. The incidence is unstable and had a mean annual increase 14.2 % per year during the studied period. A faster annual increase was observed in boys, warmer seasons, and in the outer regions of the city. If present trends continue, the number of new type 1 diabetes cases will double from 2016 to 2020, and prevalent cases will sextuple by 2025. Our results showed the incidence of childhood type 1 diabetes was rising rapidly in Shanghai. More studies are needed to analyze incidence changes in other regions of China for appropriate allocation of healthcare resources.

The growth hormone receptor (GHR) exon 3 polymorphism and its correlation with metabolic profiles in obese Chinese children.

OBJECTIVE: We investigated the correlation between the growth hormone receptor (GHR) exon 3 polymorphism and the metabolic profiles of Chinese children with obesity. SUBJECTS AND METHODS: A total of 409 obese/overweight children and 206 normal weight children were recruited. Anthropological and biochemical indexes including insulin and lipid profiles were measured. Genomic DNA was extracted from the peripheral blood leukocytes, and the GHR exon 3 polymorphism was genotyped by polymerase chain reaction. Homeostasis model of assessment for insulin resistance index (HOMA-IR) and insulin sensitivity index (ISI) were calculated using the homeostasis model. RESULTS: The frequency of the exon 3-deleted GHR (d3-GHR) polymorphism within the obese group was significantly higher than that of the control group (p < 0.05). Body mass index (BMI), fasting insulin (FIns), HOMA-IR, total cholesterol, and triglycerides were significantly lower in the d3-GHR (d3/d3 and d3/fl) group than in the full-length GHR (fl/fl, fl-GHR) group (p < 0.05). After adjustment for BMI, cholesterol level was still significantly lower and HOMA-IR was marginally lower (p = 0.079) in the d3-GHR obese group. There was no statistically significant difference in BMI, FIns, HOMA-IR, ISI, total cholesterol, or triglyceride levels between the two genotypes in the control group. CONCLUSION: We report that the d3-GHR polymorphism has a significant effect on BMI and the metabolic parameters of Chinese children with obesity. The d3 allele may have a protective effect on the development of metabolic syndrome by increasing insulin sensitivity.